"I had given up on the system," Ochoa said after embracing his weeping mother. "We have to fix it because I came close to losing my life."

Ochoa, 34, confessed to killing Nancy DePriest at a Pizza Hut in Austin in 1988, but later said he was coerced by homicide detectives.

At his request, students in the Wisconsin Innocence Project at the University of Wisconsin-Madison studied the case and found DNA evidence they said proved someone else shot DePriest.

The second- and third-year law students investigate possible wrongful convictions.

Authorities said the new evidence points to Achim Joseph Marino, a Texas inmate who confessed to DePriest's rape and murder in 1996 after a religious conversion and provided police with the gun and handcuffs he used to commit the crime.

Marino, who is serving three life sentences for other crimes, also provided mouth swabbings carrying his DNA, which was matched by the law students to evidence taken from DePriest's body.

"This is wrong, it's horrible. It's going on all over the United States. We've got to stop this," said Popp, 51. "It is my wish that the death penalty be abolished in the state of Texas so that it can no longer be used as a threat to coerce confessions from the innocent."

Ochoa, who was 22 at the time of the slaying, also testified against his then-roommate, Richard Danziger, who was convicted of raping the woman. Danziger is still in prison, where a severe beating left him unable to care for himself. His lawyers plan to ask for his release.

Ochoa said he deeply regrets Danziger's fate.

"I feel very bad about not having the courage to stand up to those police officers," he said. "I have to live with that for the rest of my life."

Austin police and the Texas Rangers are investigating how the case went wrong. Their report, to be reviewed by the U.S. attorney's office, is expected by the end of the month.

The first thing Ochoa said he would do as a free man is visit the grave of his grandfather, who died in El Paso when Ochoa was in prison.